Preparation method and application of pumpkin seed oil-based oleogel based on Pickering emulsion

Abstract

The invention discloses a preparation method and application of pumpkin seed oil-based oleogel based on a Pickering emulsion, and the preparation method of the pumpkin seed oil-based oleogel based on the Pickering emulsion comprises the following steps: taking a mixed solution of gelatin-xanthan gum-fucoidin-tea polyphenol as a water phase, taking pumpkin seed oil as an oil phase, stirring and mixing the oil phase and the water phase, and stirring and mixing to obtain the pumpkin seed oil-based oleogel based on the Pickering emulsion. The pumpkin seed oil-based oil gel based on the Pickering emulsion is obtained. The oil gel is stable in physicochemical property, can partially replace or completely replace saturated fat to be applied to snack food, for example, the oil gel not only can endow baked food with excellent sensory characteristics and nutritional characteristics, but also can play a role in delaying deterioration of products to a certain extent, and is suitable for further popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of vegetable oil processing, and in particular to a preparation method and application of a pumpkin seed oil-based oil gel based on Pickering emulsion. Background Art

[0002] Solid fats and oils are widely used in various foods because they improve the taste, texture, aroma and flavor of food. However, in recent years, with the increasing demand for healthy foods, the high content of trans fatty acids and saturated fatty acids in solid fats has made consumers increasingly concerned about their negative impact on human health. Studies have shown that excessive intake of saturated fatty acids by the human body will pose a certain threat to health. Reducing the intake of saturated fatty acids and trans fatty acids in healthy foods has become an issue that cannot be ignored. Therefore, converting liquid oils into edible soft solids as a substitute for trans fatty acids has received increasing attention.

[0003] Studies have shown that pumpkin seed oil is rich in essential fatty acids (especially linoleic acid and linolenic acid), amino acids, and trace mineral elements such as zinc and iron. Long-term consumption of pumpkin seed oil can improve human metabolism, lower cholesterol, and has certain health benefits. However, its disadvantages are also obvious. It may be due to the high degree of unsaturation in pumpkin seed oil, so it is easy to oxidize and become rancid. In addition, its poor water solubility and low oral utilization rate have greatly limited its application in food. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to propose a preparation method and application of a pumpkin seed oil-based oil gel based on Pickering emulsion. The oil gel is simple to prepare and has stable physical and chemical properties. It can replace or completely replace the use of saturated fat in snack foods.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A method for preparing a pumpkin seed oil-based oil gel based on a Pickering emulsion comprises the following steps: using a mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols as an aqueous phase and pumpkin seed oil as an oil phase, stirring and mixing the oil phase and the aqueous phase to obtain the pumpkin seed oil-based oil gel based on the Pickering emulsion.

[0007] As a possible implementation mode, further, the gelatin accounts for 1.5% of the water mass in the mixed solution, the xanthan gum accounts for 0.25% to 0.75% of the water mass in the mixed solution, the fucoidan accounts for 2% to 4% of the water mass in the mixed solution, and the tea polyphenols account for 0.04% to 0.08% of the water mass in the mixed solution.

[0008] As a possible implementation manner, further, the oil phase and the water phase are mixed in a volume ratio of 7:3.

[0009] As a possible implementation manner, the oil phase and the water phase are further stirred at 4° C. and 1200-1800 r / min for 20 min to obtain a pumpkin seed oil-based oil gel based on the Pickering emulsion.

[0010] As a possible implementation mode, further, the method for preparing the mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols comprises the following steps:

[0011] 1) Prepare gelatin sol, stir at high speed, and let it stand overnight to fully hydrate;

[0012] 2) adding xanthan gum, fucoidan and tea polyphenol powder to the gelatin solution in sequence;

[0013] 3) adjusting the pH value of the mixed solution system to 6-7, and heating and stirring to mix the entire system evenly to obtain a mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols.

[0014] As a possible implementation manner, further, high-speed stirring is performed at 1200-1800 r / min for 30 min in a water bath at 80° C.

[0015] The present invention also provides a pumpkin seed oil-based oil gel based on Pickering emulsion, which is prepared by the above-mentioned preparation method. Among them, the pumpkin seed oil-based oil gel based on Pickering emulsion can partially replace or completely replace the application of saturated fat in leisure food. Specifically, the pumpkin seed oil-based oil gel based on Pickering emulsion can be applied to baked foods such as cakes, which can not only give the baked foods better sensory properties and nutritional properties, but also play a role in delaying product deterioration to a certain extent.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1) The oil gel prepared by the present invention not only has stable physical and chemical properties, but also can partially or completely replace saturated fat and is widely used in snack foods. Compared with traditional emulsions, Pickering emulsions can more stably embed active substances and improve the oxidative stability of oils and fats, so they have broad application prospects in the food industry.

[0018] 2) The oil gel prepared by the present invention can effectively load tea polyphenols, an antioxidant active substance, to achieve sustained release of tea polyphenols, thereby giving the product better sensory quality during storage and good storage resistance.

[0019] 3) The pumpkin seed oil-based oil gel based on Pickering emulsion in the present invention uses natural proteins and polysaccharides such as gelatin, xanthan gum, fucoidan and tea polyphenols as the aqueous phase and pumpkin seed oil as the oil phase, which is non-toxic, safe and reliable, has a simple preparation process and a wide range of applications. Proteins and polysaccharides are high-quality food nutritional components. At the same time, gelatin, xanthan gum and fucoidan form a complex macromolecular network structure through interaction, and can be used as a potential gelling agent to structure oils and fats to prepare oil gels, which provides a new idea for the development of nutritious and healthy plastic fat substitutes.

[0020] 4) Pumpkin seed oil is rich in essential fatty acids (especially linoleic acid and linolenic acid), but it is easy to oxidize and become rancid due to its high unsaturation, and its poor water solubility and low oral availability greatly limit its application in food. The present invention constructs a pumpkin seed oil-based oil gel (structured oil) based on Pickering emulsion, which is an effective means to improve the plasticity of oil by structuring liquid oil with a gelling agent, and is a new strategy for constructing a zero-trans, low-saturated fatty acid plastic fat substitute. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 The macroscopic and microscopic structures of xanthan gum oil gels with different concentrations in Example 1; (Note: X1-X5 represent xanthan gum mass fractions of 0, 0.25%, 0.5%, 0.75%, and 1%, respectively)

[0023] Figure 2 The macroscopic and microscopic structures of fucoidan oil gels with different concentrations in Example 2; (Note: C1-C5 represent fucoidan mass fractions of 1%, 2%, 3%, 4%, and 5%, respectively)

[0024] Figure 3 The macroscopic and microscopic structures of tea polyphenol oil gels of different concentrations in Example 3; (Note: T1-T5 represent tea polyphenol mass fractions of 0.02%, 0.04%, 0.06%, 0.08%, and 0.1%, respectively)

[0025] Figure 4 This is a comparison of the appearance of xanthan gum, fucoidan and tea polyphenol oil gels of different concentrations in heating and freeze-thaw treatment Examples 1 to 3;

[0026] Figure 5Changes in TBARS of the oleogel and pumpkin seed oil prepared with the optimal ratio during storage; (the optimal ratio is: xanthan gum accounts for 0.5% of the water mass in the mixed solution, fucoidan accounts for 3% of the water mass in the mixed solution, and tea polyphenols accounts for 0.06% of the water mass in the mixed solution)

[0027] Figure 6 This is a comparison chart of cakes made with oil gel and butter prepared with the optimal ratio after 15 days of storage;

[0028] Figure 7 This is a sensory evaluation comparison chart of cakes made with oil gel and butter prepared with the optimal ratio;

[0029] Figure 8 A comparison chart of the texture changes of two cakes made with oil gel and butter prepared with the optimal ratio within 15 days;

[0030] Fig. 9 This is a comparison chart of the changes in malondialdehyde in cakes made from oil gel and butter prepared with the optimal ratio during storage. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] The present invention provides a method for preparing a pumpkin seed oil-based oil gel based on a Pickering emulsion, which specifically comprises the following steps:

[0033] 1) First, a gelatin solution is prepared, wherein the gelatin accounts for 1.5% of the mass of water in the gelatin solution, and after high-speed stirring, the solution is allowed to stand overnight to be fully hydrated;

[0034] 2) then sequentially adding xanthan gum, fucoidan and tea polyphenol powder to the gelatin solution obtained in step 1) to obtain a mixed solution system; wherein the xanthan gum accounts for 0.25% to 0.75% of the water mass in the mixed solution, the fucoidan accounts for 2% to 4% of the water mass in the mixed solution, and the tea polyphenol accounts for 0.04% to 0.08% of the water mass in the mixed solution;

[0035] 3) adjusting the pH value of the mixed solution system obtained in step 2) to 6-7, stirring at a high speed of 1200-1800 r / min for 30 min in a water bath at 80° C. to mix the entire system uniformly, and obtaining a mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols;

[0036] 4) Finally, pumpkin seed oil is used as the oil phase, the mixed solution obtained in step 3) is used as the water phase, the oil phase and the water phase are mixed in a volume ratio of 7:3 (v / v), and stirred at 4°C at 1200-1800 r / min for 20 min to obtain a pumpkin seed oil-based oil gel based on Pickering emulsion. The oil gel has stable physical and chemical properties and can partially or completely replace saturated fat in snack foods. For example, it can not only give baked foods better sensory properties and nutritional properties, but also play a role in delaying product deterioration to a certain extent.

[0037] Example 1

[0038] The preparation method of pumpkin seed oil-based oil gel based on Pickering emulsion in this embodiment comprises the following specific steps:

[0039] 1) First, a gelatin solution is prepared, wherein the gelatin accounts for 1.5% of the mass of water in the gelatin solution, and after high-speed stirring, the solution is allowed to stand overnight to be fully hydrated;

[0040] 2) Then, xanthan gum, fucoidan and tea polyphenol powder are added to the gelatin solution obtained in step 1) in sequence to obtain a mixed solution system; wherein the fucoidan accounts for 3% of the water mass in the mixed solution, and the tea polyphenol accounts for 0.06% of the water mass in the mixed solution; in this embodiment, the amount of xanthan gum added is subjected to multiple parallel comparisons, wherein the amount of xanthan gum added accounts for 0%, 0.25%, 0.5%, 0.75% and 1% of the water mass in the mixed solution respectively;

[0041] 3) adjusting the pH value of the mixed solution system obtained in step 2) to 6-7, stirring at a high speed of 1200-1800 r / min for 30 min in a water bath at 80° C. to mix the entire system uniformly, and obtaining a mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols;

[0042] 4) Finally, pumpkin seed oil is used as the oil phase, the mixed solution obtained in step 3) is used as the water phase, the oil phase and the water phase are mixed in a volume ratio of 7:3 (v / v), and stirred at 4° C. at 1200-1800 r / min for 20 min to obtain a pumpkin seed oil-based oil gel based on Pickering emulsion.

[0043] Example 2

[0044] The preparation method of pumpkin seed oil-based oil gel based on Pickering emulsion in this embodiment comprises the following specific steps:

[0045] 1) First, a gelatin solution is prepared, wherein the gelatin accounts for 1.5% of the mass of water in the gelatin solution, and after high-speed stirring, the solution is allowed to stand overnight to be fully hydrated;

[0046] 2) Then, xanthan gum, fucoidan and tea polyphenol powder are added to the gelatin solution obtained in step 1) in sequence to obtain a mixed solution system; wherein the xanthan gum accounts for 0.5% of the water mass in the mixed solution, and the tea polyphenol accounts for 0.06% of the water mass in the mixed solution; in this embodiment, the amount of fucoidan added is subjected to multiple parallel comparisons, wherein the amount of fucoidan added accounts for 1%, 2%, 3%, 4% and 5% of the water mass in the mixed solution respectively;

[0047] 3) adjusting the pH value of the mixed solution system obtained in step 2) to 6-7, stirring at a high speed of 1200-1800 r / min for 30 min in a water bath at 80° C. to mix the entire system uniformly, and obtaining a mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols;

[0048] 4) Finally, pumpkin seed oil is used as the oil phase, the mixed solution obtained in step 3) is used as the water phase, the oil phase and the water phase are mixed in a volume ratio of 7:3 (v / v), and stirred at 4° C. at 1200-1800 r / min for 20 min to obtain a pumpkin seed oil-based oil gel based on Pickering emulsion.

[0049] Example 3

[0050] The preparation method of pumpkin seed oil-based oil gel based on Pickering emulsion in this embodiment comprises the following specific steps:

[0051] 1) First, a gelatin solution is prepared, wherein the gelatin accounts for 1.5% of the mass of water in the gelatin solution, and after high-speed stirring, the solution is allowed to stand overnight to be fully hydrated;

[0052] 2) Then, xanthan gum, fucoidan and tea polyphenol powder are added to the gelatin solution obtained in step 1) in sequence to obtain a mixed solution system; wherein the xanthan gum accounts for 0.5% of the mass of water in the mixed solution, and the fucoidan accounts for 3% of the mass of water in the mixed solution; in this embodiment, the amount of tea polyphenol added is subjected to multiple parallel comparisons, wherein the amount of tea polyphenol added accounts for 0.02%, 0.04%, 0.06%, 0.08% and 0.1% of the mass of water in the mixed solution respectively;

[0053] 3) adjusting the pH value of the mixed solution system obtained in step 2) to 6-7, stirring at a high speed of 1200-1800 r / min for 30 min in a water bath at 80° C. to mix the entire system uniformly, and obtaining a mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols;

[0054] 4) Finally, pumpkin seed oil is used as the oil phase, the mixed solution obtained in step 3) is used as the water phase, the oil phase and the water phase are mixed in a volume ratio of 7:3 (v / v), and stirred at 4° C. at 1200-1800 r / min for 20 min to obtain a pumpkin seed oil-based oil gel based on Pickering emulsion.

[0055] Sample characterization and testing

[0056] The oil gel samples prepared in Examples 1 to 3 were characterized and tested respectively. The oil gel sample characterization and testing methods include:

[0057] 1. Observation of appearance structure and microstructure

[0058] The microstructure of the Pickering emulsion oil gel was observed under normal light with a 10x eyepiece and a 20x objective using a polarizing microscope, and photographed using a microscopic camera system.

[0059] 2. Determination of particle size and potential

[0060] Particle size and potential were determined according to the method in the literature. The average particle size and Zeta potential of Pickering emulsion oil gel were determined at 25°C using a nanoparticle size and Zeta potential analyzer. The sample was added to the circulation pool until the shading reached about 12% before measurement. The potential was measured using a Malvern nanoparticle sizer. The sample was diluted 100 times, the sample dilution was drawn into the potential cell, and the potential cell was placed in the nanoparticle sizer to measure the potential. Each sample was measured 3 times, and the results were averaged.

[0061] 3. Determination of thermal stability and freeze-thaw stability

[0062] The sealed Pickering emulsion oil gel sample was placed in a boiling water bath for 15 minutes, and then immediately placed in an ice bath to cool to room temperature and observe its fluidity. The Pickering emulsion oil gel sample was frozen at -20°C for 24 hours and then thawed at 25°C for 4 hours. The appearance of the treated oil gel was observed, and its hot melt stability and freeze-thaw stability were observed.

[0063] 4. Determination of oxidative stability of oil gel

[0064] 10 g of Pickering emulsion oil gel was placed in a 20 mL serum bottle and cultured in an oven at 60°C for 14 days to accelerate lipid oxidation. The contents of primary oxidation products (lipid hydroperoxides) and secondary oxidation products (malondialdehyde) in the oil gel were measured every 2 days. Pure pumpkin seed oil was used as the control group to measure the TBARS changes of the oil gel and cake.

[0065] Dissolve 0.375g of thiobarbituric acid (0.375%, w / v) and 15g of trichloroacetic acid (15%, w / v) in 100mL of 0.25M hydrochloric acid to prepare thiobarbituric acid reagent. Take 4ml of thiobarbituric acid reagent and add 0.5g of oil gel or 1.0g of cake to mix. Heat the mixture in a water bath for 15min, then immediately cool to room temperature under running water, and then centrifuge the mixture at 8000rpm for 15min. After centrifugation, take the clear liquid and measure the absorbance at 532nm. The results are expressed as mgMDA / kg sample. Using malondialdehyde as the standard, calculate the concentration change of sample TBARS.

[0066] 5. Application of pumpkin seed oil-based oil gel based on Pickering emulsion in cakes

[0067] ①Cake making

[0068] In order to evaluate the potential application of oil gel as a margarine substitute, cakes were made with margarine and Pickering emulsion oil gel. The preparation method is as follows: 40g of margarine and Pickering emulsion oil gel were mixed with 37.5g of white sugar, then 40g of fresh eggs were added and quickly beaten with a mixer, and finally 0.25g of salt, 45g of low-gluten wheat flour, and 1.35g of baking powder were added, and stirred evenly for later use. 30g of batter was weighed for baking. The oven temperature was set to 165℃ and baked for 20min.

[0069] ② Sensory evaluation

[0070] Table 1 Cake sensory evaluation standards

[0071]

[0072]

[0073] ③Texture analysis of cake

[0074] The texture profile of the cakes was analyzed on the day of preparation and at 25°C using a texture analyzer. The samples were compressed in two steps at a speed of 1.0 mm / min using a TA 10 circular probe, with two steps of compression at 1 cm from the center of the cake and 50% deformation. The force measured in these two cycles was plotted as a function of time to obtain the TPA curve, and the experiment was repeated 3 times for each sample.

[0075] ④ Determination of oxidative stability of cake

[0076] Two samples were cultured in an oven at 60°C for 15 days to accelerate lipid oxidation. The contents of primary oxidation products (lipid hydroperoxides) and secondary oxidation products (malondialdehyde) of the oil gel were measured every 2 days (storage for one day at 60°C is equivalent to storage for one month at 20°C). Finally, they were used to evaluate the antioxidant properties of cakes made with Pickering emulsion oil gel and margarine cakes.

[0077] The macroscopic and microscopic structures of xanthan gum oil gels with different concentrations prepared in Example 1 are shown in the attached figure. Figure 1 The macroscopic and microscopic structures of the fucoidan oil gels with different concentrations prepared in Example 2 are shown in the attached Figure 2 The macroscopic and microscopic structures of tea polyphenol oil gels with different concentrations prepared in Example 3 are shown in the attached Figure 3 shown.

[0078] The particle size and potential changes of the oil gel samples of Examples 1-3 are shown in Table 2 below:

[0079] Table 2 Particle size and potential changes of xanthan gum, fucoidan and tea polyphenol oil gels at different concentrations

[0080]

[0081] Note: Different letters in ac indicate that the particle size or absolute value of potential of the same component has significant difference (P<0.05).

[0082] As can be seen from Table 2, when the mass of xanthan gum, fucoidan and tea polyphenols account for 0.5%, 3% and 0.06% of the water in the mixed solution respectively, the particle size of the corresponding oil gel sample has a minimum value, and at the same time the absolute value of the potential has a maximum value, which shows that under the above conditions, the degree of aggregation of pumpkin seed oil-based oil gel particles based on Pickering emulsion is low, the electrostatic repulsion between particles increases, and the system has better stability.

[0083] See attached Figure 4As shown in the figure, it can be seen that after melting in boiling water, it was quickly bathed in ice water to room temperature. In the first group X1~X5, X3 and X4 did not undergo obvious changes (inverted and did not flow), and the rest of the groups dropped or flowed slowly to varying degrees. It can be seen that X3 and X4 oil gels have good thermal stability. After melting in boiling water, it was quickly bathed in ice water to room temperature. In the second group C1~C5, C2~C4 did not undergo obvious changes (inverted and did not flow), and C1 and C5 showed a slow flow trend; it can be seen that C2~C4 oil gels have good thermal stability. After melting in boiling water, it was quickly bathed in ice water to room temperature. In the third group T1~T5, T3 and T5 did not undergo obvious changes (inverted and did not flow), and the rest of the groups dropped or flowed slowly to varying degrees. It can be seen that T3 and T5 oil gels have good thermal stability.

[0084] After freeze-thaw treatment, in the first group X1~X5, the emulsification effect of X1 became worse, the oil droplet embedding was not sufficient and the oil droplets were obvious, and the other groups had good oil droplet embedding and stability, but except for X3, the other groups all showed inversion and falling; it can be seen that X3 has good freeze-thaw stability. After freeze-thaw treatment, in the second group C1~C5, C1~C5 had good oil droplet embedding and stability, but except for C3, the other groups all showed falling, which shows that C3 has good freeze-thaw stability. After freeze-thaw treatment, in the third group T1~T5, except for T1, the other groups remained intact.

[0085] In summary, when the mass of xanthan gum, fucoidan and tea polyphenols in the mixed solution is 0.25% to 0.75%, 2% to 4%, 0.04% to 0.08% respectively, the oil gel has excellent macroscopic and microscopic properties, thermal stability and freeze-thaw stability. When the mass of xanthan gum, fucoidan and tea polyphenols in the mixed solution is 0.5%, 3% and 0.06% respectively, the oil gel has the best oxidative stability, which is consistent with the particle size and potential change results of xanthan gum, fucoidan and tea polyphenols oil gels with different concentrations in the previous text. That is, the optimal ratio of xanthan gum, fucoidan and tea polyphenols in the present invention is: xanthan gum accounts for 0.5% of the mass of water in the mixed solution, fucoidan accounts for 3% of the mass of water in the mixed solution, and tea polyphenols accounts for 0.06% of the mass of water in the mixed solution.

[0086] See attached Figure 5As shown in the figure, it can be seen that as the accelerated oxidation test progresses, the TBARS of both groups of samples continue to increase. During storage, the TBARS of the ordinary liquid pumpkin seed oil group (control group) is much higher than that of the oil-structured oil gel group. This is mainly because after the tea polyphenols form a complex with the fucoidan-gelatin system, a stable Pickering emulsion is further formed. At this time, the encapsulated tea polyphenols, an antioxidant active ingredient, can effectively eliminate the oxidative free radicals on the interface to the maximum extent, thereby preventing the oxidation of the oil. In addition, the colloidal particles form a thick interface on the oil droplets, generating a strong spatial repulsion to reduce the contact between the oil and oxygen.

[0087] In addition, the oil gel prepared under the above conditions is applied to cake preparation. The study shows that compared with cakes made with margarine, cakes made with Pickering emulsion oil gel have better sensory properties and less surface cracking. The two groups of cakes were placed for fifteen days to observe their appearance changes. The cakes made with butter began to have wrinkles on the sixth day, and then the skin collapsed. Mold spots were observed on the twelfth day, and the mold spots were more obvious on the fifteenth day. The cakes made with oil gel did not have obvious wrinkles, the surface was relatively smooth, and no mold spots were seen with the naked eye on the fifteenth day. In terms of texture, the use of oil gel can improve the hardness and chewiness of the cake to a certain extent. From the accelerated experiment, the oil gel prepared by the present invention can slow down the increase of the malondialdehyde content of the cake compared with butter. This may be because the tea polyphenols in the oil gel are an antioxidant active ingredient that can play a role in delaying product deterioration to a certain extent.

[0088] See attached Figure 6 As shown, the oil gel prepared with the optimal ratio is applied to cake preparation. The study shows that compared with cakes made with margarine, cakes made with Pickering emulsion oil gel have better sensory properties and less surface cracking. The two groups of cakes were placed for fifteen days to observe the changes in their appearance. The cakes made with butter began to have wrinkles on the sixth day, and then the skin collapsed. Mold spots were observed on the twelfth day, and the mold spots were more obvious on the fifteenth day. The cakes made with oil gel did not have obvious wrinkles, the surface was relatively smooth, and no mold spots were seen with the naked eye on the fifteenth day. It can be seen that the oil gel prepared by the present invention has the effect of delaying product deterioration.

[0089] See attached Figure 7 As shown, according to the radar chart, it can be seen that the flavor of cakes made with butter is better than that of cakes made with oil gel, but the difference is not large; the sourness and sweetness of the two are basically the same; the appearance, color, texture, softness of the mouthfeel, etc. of cakes made with oil gel are better than those made with margarine. The oil gel prepared by the present invention shows great potential in the field of replacing or partially replacing solid fats.

[0090] See attached Figure 8As shown in the figure, it can be seen that compared with the use of butter, the use of oil gel can improve the hardness and chewiness of the cake to a certain extent.

[0091] See attached Fig. 9 As shown, from the accelerated experiment, compared with butter, the oil gel prepared by the present invention can slow down the increase of the malondialdehyde content in the cake and delay the deterioration of the cake.

[0092] In summary, the present invention constructs an aqueous phase system of a gelatin-xanthan gum-fucoidan-tea polyphenol mixed solution, and uses pumpkin seed oil with health benefits as the oil phase to prepare a pumpkin seed oil-based oil gel based on Pickering emulsion. The prepared oil gel has stable physical and chemical properties and can partially or completely replace the application of saturated fat in snack foods, such as adding it to baked products such as cakes, which can not only give baked foods better sensory properties and nutritional properties, but also play a role in delaying product deterioration to a certain extent.

[0093] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a pumpkin seed oil-based oleogel based on Pickering emulsion, characterized in that: A mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols is used as an aqueous phase, and pumpkin seed oil is used as an oil phase. The oil phase and the aqueous phase are stirred and mixed to obtain a pumpkin seed oil-based oil gel based on a Pickering emulsion.

2. The method for preparing a pumpkin seed oil-based oil gel based on a Pickering emulsion according to claim 1, characterized in that: The gelatin accounts for 1.5% of the water mass in the mixed solution, the xanthan gum accounts for 0.25% to 0.75% of the water mass in the mixed solution, the fucoidan accounts for 2% to 4% of the water mass in the mixed solution, and the tea polyphenols account for 0.04% to 0.08% of the water mass in the mixed solution.

3. The method for preparing a pumpkin seed oil-based oleogel based on a Pickering emulsion according to claim 1, characterized in that: The oil phase and the water phase are mixed in a volume ratio of 7:

3.

4. The method for preparing a pumpkin seed oil-based oleogel based on a Pickering emulsion according to claim 1, characterized in that: The oil phase and the water phase were stirred at 4° C. and 1200-1800 r / min for 20 min to obtain a pumpkin seed oil-based oil gel based on a Pickering emulsion.

5. The method for preparing a pumpkin seed oil-based oil gel based on Pickering emulsion according to claim 2, characterized in that: The method for preparing the mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols comprises the following steps: 1) Prepare gelatin sol, stir at high speed, and let it stand overnight to fully hydrate; 2) adding xanthan gum, fucoidan and tea polyphenol powder to the gelatin solution in sequence; 3) adjusting the pH value of the mixed solution system to 6-7, and heating and stirring to mix the entire system evenly to obtain a mixed solution of gelatin-xanthan gum-fucoidan-tea polyphenols.

6. The method for preparing a pumpkin seed oil-based oil gel based on Pickering emulsion according to claim 1, characterized in that: Stir at a high speed of 1200-1800 r / min for 30 min in a 80°C water bath.

7. A pumpkin seed oil-based oil gel based on Pickering emulsion, characterized in that It is prepared by the preparation method according to any one of claims 1 to 6.

8. A use of a pumpkin seed oil-based oil gel based on a Pickering emulsion as claimed in claim 7, characterized in that: The pumpkin seed oil-based oil gel based on Pickering emulsion can replace saturated fat in food.

9. The use according to claim 8, characterized in that: The Pickering emulsion-based pumpkin seed oil-based oil gel is applied to baked goods.

10. The use according to claim 8, characterized in that: The baked food is a cake.

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